Ford F-350 axle ratings
We purchased a new Excel Winslow 31IKE last October. It has a 17,500# GVWR. Our F-250 diesel pulls it just fine but a trip to the scale yesterday shows we are 240# over our RAWR of 6100#. I can not...
Forum Discussion
For a more apple-apple comparison I looked at the 6.4L Auto ratio's with 3.73 and 4.10 compared to the 6.7L Auto ratio's with 3.55.
The 6.7L is a 6 speed, but has 2 OD's so there are 3 gears before "direct", as mentioned the auto used behind the 6.7 doesn't have a direct but a 1.15:1.
For a 2008 with 3.73's
1st is lower in the 6.7 by 21%
2nd is lower in the 6.7 by 0.4%
3rd is taller in the 6.7 by 6%
4th is lower in the 6.7 by 9.5%
5th is lower in the 6.7 by 15%
Comparing 6th (6.7) to 5th (6.4) the 6.4 is only 10% taller than the 2nd OD.
For a 2008 with 4.10's
1st is lower in the 6.7 by 10%
2nd is taller in the 6.7 by 9%
3rd is taller in the 6.7 by 14.5%
4th is taller in the 6.7 by 0.5%
5th is lower in the 6.7 by 5%
Comparing 6th (6.7) to 5th (6.4) the 6.4 is 18% taller than the 2nd OD.
As you can see the trans ratio is very important, and probably why Ford doesn't offer a 3.73 or 4.10 in the 250/350 pickups anymore. They have chosen to do most of their gearing reduction in the trans.
The 6.7L is a 6 speed, but has 2 OD's so there are 3 gears before "direct", as mentioned the auto used behind the 6.7 doesn't have a direct but a 1.15:1.
For a 2008 with 3.73's
1st is lower in the 6.7 by 21%
2nd is lower in the 6.7 by 0.4%
3rd is taller in the 6.7 by 6%
4th is lower in the 6.7 by 9.5%
5th is lower in the 6.7 by 15%
Comparing 6th (6.7) to 5th (6.4) the 6.4 is only 10% taller than the 2nd OD.
For a 2008 with 4.10's
1st is lower in the 6.7 by 10%
2nd is taller in the 6.7 by 9%
3rd is taller in the 6.7 by 14.5%
4th is taller in the 6.7 by 0.5%
5th is lower in the 6.7 by 5%
Comparing 6th (6.7) to 5th (6.4) the 6.4 is 18% taller than the 2nd OD.
As you can see the trans ratio is very important, and probably why Ford doesn't offer a 3.73 or 4.10 in the 250/350 pickups anymore. They have chosen to do most of their gearing reduction in the trans.
